2 DOSAGE AND ADMINISTRATION
The dosage (based on body weight in mg/kg/day), rates of administration, and mode of administration for both adults and pediatric patients are individually determined and adapted during the course of therapy based on the severity of the patient's iron overload. The minimum daily dose of deferoxamine mesylate is 20 mg/kg/day for both adults and pediatric patients. The maximum daily dose is 40 mg/kg/day for pediatric patients and 60 mg/kg/day for adults.
2.1 Recommended Dosage for Treatment of Acute Iron Intoxication for Adults and Pediatric Patients
Intramuscular (IM) Administration
Use for all patients not in shock.
The initial recommended dose of Deferoxamine Mesylate for injection is 1,000 mg intramuscularly (IM) once. If needed based on the clinical response, administer subsequent doses of 500 mg every 4 hours to 12 hours. The maximum recommended daily dose is 6,000 mg in 24 hours.
Intravenous (IV) Administration
Administer Deferoxamine Mesylate for injection intravenously (IV) to patients in a state of cardiovascular collapse and then only by slow infusion. As soon as the clinical condition of the patient permits, intravenous administration should be discontinued, and the drug should be administered intramuscularly.
The initial recommended IV dose of Deferoxamine Mesylate for injection is 1,000 mg administered at an infusion rate of up to 15 mg/kg/hr. If needed based on the clinical response administer additional doses of 500 mg over 4 hours to 12 hours at a slower infusion rate of up to 125 mg/hr. The maximum recommended daily dose is 6,000 mg in 24 hours.
2.2 Recommended Dosage for Treatment of Chronic Iron Overload for Adults and Pediatric Patients
Subcutaneous Infusion Administration
The average daily dose of Deferoxamine Mesylate for injection is usually between 20 and 60 mg/kg. In general patients with serum ferritin level below 2,000 ng/mL require about 25 mg/kg/day. Patients with serum ferritin level between 2,000 and 3,000 ng/mL require about 35 mg/kg/day. Patients with higher serum ferritin may require up to 55 mg/kg/day. It is not advisable to regularly exceed an average daily dose of 50 mg/kg/day except when very intensive chelation is needed in patients who have completed growth. If ferritin levels fall below 1,000 ng/mL, the risk of Deferoxamine mesylate toxicity increases; it is important to monitor these patients particularly carefully and perhaps to consider lowering the total weekly dose. The doses specified here are the average daily doses. Since most patients use Deferoxamine mesylate less than 7 days a week, the actual dose per infusion usually differs from the average daily dose; e.g. if an average daily dose of 40 mg/kg/day is required and the patient wears the pump 5 nights a week, each infusion should contain 56 mg/kg.
Slow subcutaneous infusion using a portable, light-weight infusion pump over a period of 8 to 12 hours is regarded as effective and especially convenient for ambulatory patients, but may also be given over a 24-hour period. Deferoxamine mesylate should normally be used with the pump 5 to 7 times a week. Deferoxamine mesylate is not formulated to support subcutaneous bolus injection.
Deferoxamine Mesylate for injection can be administered intravenously if needed in patients with intravenous access.
The recommended dose of Deferoxamine Mesylate for injection in adults is 40 mg/kg/day to 50 mg/kg/day over 8 hours to 12 hours at a rate of up to 15 mg/kg/hour for 5 days to 7 days per week. Maximum dose is 60 mg/kg/day.
The recommended dose of Deferoxamine Mesylate for injection in pediatric patients is 20 mg/kg/day to 40 mg/kg/day over 8 hours to 12 hours for 5 days to 7 days per week. The maximum recommended daily dose is 40 mg/kg/day until growth (body weight and linear growth) has ceased.
In case of missed doses, Deferoxamine Mesylate for injection may be administered prior to or following same day blood transfusion (for example, 1 gram over 4 hours on the day of transfusion); however, the contribution of this mode of administration to iron balance is limited. Deferoxamine Mesylate for injection should not be administered concurrently with the blood transfusion as this can lead to errors in interpreting side effects such as rash, anaphylaxis and hypotension.
If given intramuscularly, the recommended dose of Deferoxamine Mesylate for injection is 500 mg to 1,000 mg per day. The maximum recommended daily dose is 1,000 mg per day.
Reconstitute Deferoxamine Mesylate for injection prior to administration. Deferoxamine Mesylate for injection should be further diluted for intravenous infusion. Use appropriate aseptic technique.
Reconstitute each vial of Deferoxamine Mesylate for injection with Sterile Water for Injection, USP per Table 1. Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit. Do not use if visibly opaque particles, discoloration or foreign particles are observed. The reconstituted Deferoxamine Mesylate for injection solution is an isotonic, clear and colorless to slightly-yellowish solution. Discard unused portion.
Route of Administration
Amount of Sterile Water for Injection, USP for Reconstitution
Concentration After Reconstitution
If not used immediately, store at room temperature between 20°C to 25°C (68°F to 77°F), excursions permitted between 15°C and 30°C (59°F and 86°F), for a maximum period of 24 hours. Do not refrigerate reconstituted solution.
2.4 Management of Vitamin C Deficiency
Patients with iron overload usually become vitamin C deficient, probably because iron oxidizes the vitamin. As an adjuvant to iron chelation therapy, vitamin C in doses up to 200 mg for adults may be given in divided doses, starting after an initial month of regular treatment with Deferoxamine Mesylate for injection [see Warnings and Precautions (5.7)]. Vitamin C increases availability of iron for chelation. In general, 50 mg daily suffices for pediatric patients under 10 years old and 100 mg daily for older pediatric patients. Larger doses of vitamin C fail to produce any additional increase in excretion of iron complex.